WorldFish scientist Yumiko Kura presents on findings from the Yali Falls Hydropower Dam in Vietnam, making a strong case for local communities to gain access and use rights to the reservoir for multiple uses. This research was part of the Challenge Program for Water and Food and now falls under the CGIAR Research Program on Water, Land and Ecosystems. Find out more about our work in the Mekong: http://wle.cgiar.org/focal-regions/southeastasia/

1. Understanding water benefit trade-offs
in the Lower Mekong Basin
example from a hydropower reservoir in
Vietnam
Presentation for the 7th Annual ESP Conference
8-12 September 2014, San Jose, Costa Rica
By Yumiko Kura, WorldFish – Greater Mekong Region
on behalf of: Vũ Xuân Nguyệt Hồng, Benoit Laplante, Tarek Ketelsen,
Hồ Công Hòa, and Nguyễn Việt Anh

2. OUTLINE
1. Study area
2. Study approach and methods
3. Results of households survey
4. Results of scenario analysis
5. Conclusions

3. STUDY AREA
 Yali Hydropower Dam
became fully operational in
2002
 Resettlement of 12
villages, 8,475 people
between 1994 – 2001
 Reservoir exclusively
managed for hydropower
generation
 Ambitious growth targets
for two provinces
 1 in 100 year scale water
shortages experienced in
2010-2011 dry season

4. STUDY APPROACH AND METHODS
 Purpose:
 Illustrate future potential for multiple uses of Yali reservoir water
and highlight the need for coordination of water management
strategies in Kon Tum and Gia Lai provinces.
 Methodology:
• Assessment of water uses and benefits for local communities
based on a survey of 350 households living near the reservoir
• Future water demand estimates based on socioeconomic
development plans at district and provincial levels
• Scenario analysis of water availability and allocation trade-offs
using hydrological models

5. RESEARCH QUESTIONS
 What are the main sources of water that support the
livelihoods of the households in the villages around the
reservoir and how much do different sources of water
contribute to the villagers’ economic activities?
 What would be the trade-offs between single use and
multiple uses of reservoir water, taking into
consideration the seasonal differences in water
availability and demand?

6. ANNUAL INCOME PORTFOLIO OF SURVEYED COMMUNITIES
Economic activity
Average household income / year
(n = 350)
1000 VND USD % of Total
1. Agriculture 48246.4 2,412 79.2%
Of which,
Farming 42904.0 2,145 70.1%
Livestock 2999.4 150 4.8%
Fishery 795.7 39.8 1.3%
Forestry 1635.6 81.8 3.0%
2. Non-agriculture 12730.4 636.5 20.8%
3. Total 61,204 3,060.2 100%
• Largest contribution to household income comes from production of
industrial cash crops—coffee, rubber, cinnamon, cassava
• Other food crops – incl. rice, maize, and vegetables, are grown primarily
for home consumption
• Coffee is 100% irrigated, rice is 53% irrigated

7. WATER SOURCES USED BY SURVEYED HOUSEHOLDS (%)
Water Uses River/Stream
• Public and private wells are the most importance source of water for
domestic uses and livestock
• Small rivers/streams, springs, public wells are the main water source
for crop irrigation
• Use of Yali reservoir water is limited to fishing and irrigation activities
• Use of Yali reservoir for non-hydropower purposes is only tolerated,
not officially permitted
Rain Water
/Springs
Tap Water Wells
Yali
Reservoir
Drinking 10 1 6 80 0
Bathing 9 6 5 78 1
Washing 9 6 5 76 0
Irrigation (incl. river
36 30 6 22 4
bank garden)
Fishing 0 n/a n/a n/a 9
Livestock watering 8 0 0 50 0
Transportation 0 n/a n/a 0

8. WATER BENEFITS BY USE AND USER
Importance of water resource dependent activities
Local communities (based on household survey)
Yali hydropower company (based on
secondary data)
Water Use
% of surveyed
HH engaged
in the activity
Production
output
$/HH/year
(for HHs
engaged in
the activity)
Production
output per
water use
($/M3)
% kept for
home
consumption
Value of food
crop kept for
home
consumption
($/HH/year)
Total hydropower
output to the
company ($/year)
Hydropower
output per
water used
($/M3)
Fisheries 12.6
1,289
n/a 29 374
Agriculture 81.3
4,273
0.276 5.39 230
Domestic use
(drinking,
washing)
100 0.414
Hydropower 47,292,000 0.007
Aquaculture 1.4 n/a 0.781
• From Water productivity perspective, economic benefit per M3 of water
derived by hydropower company is far below the benefits the local
communities derive from water for any single activity
• The amount of the water that is required to generate the hydropower
outputs is 7.2 billion M3/year

9. MULTIPLE WATER USE SCENARIOS FOR YALI RESERVOIR
 Scenario 1 (baseline) – Single
use: Reservoir is managed
exclusively for hydropower
production.
 Scenario 2 – Multiple-use
(rural): Reservoir water is used
to meet 100% of the total water
demand by the local
communities within a 2km
buffer zone around the reservoir
(annual water demand is 81.3
million m3).
 Scenario 3 – Multiple-use
(urban and rural): Scenario 2
plus the water demand of
provincial capital Kon Tum City
in 2010 (Scenario 3a) and in
2030 (Scenario 3b), water
demand of 165 million m3 and
174.7 million m3, respectively.

10. SCENARIO RESULTS
Difference in Reservoir Storage and Energy Production
Between Scenario 1 and Scenario 2
0.0%
-1.0%
-2.0%
-3.0%
-4.0%
-5.0%
-6.0%
-7.0%
-8.0%
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Difference(%)
Power generation Reservoir storage
 Scenario 2: hydropower production in dry season is reduced by
3.5% on average compared to the baseline, representing a loss of
approximately US$450,000 in energy production.
 Scenario 3: the loss is approximately US$1 million.

11. CONCLUSIONS
 Increased access to the water resources in Yali Reservoir can
potentially create higher economic benefits to local communities,
especially in water shortage conditions, at little cost to hydropower
production
 The commonly held notion that hydropower is the best way to
maximize the economic benefits of water, and that hydropower needs
to be prioritized as an exclusive water user, is a misconception in this
context
 More research is needed to address several information gaps before
any actual decisions on reservoir water management are made:
• Technical feasibility and cost of using and distributing the Yali
Reservoir water for non-hydropower uses
• Better understanding of groundwater availability, recharge rates,
and withdrawal potential to meet future demands
• Most appropriate ways to maximize the benefit of additional water
for the local communities

12. FOR MORE INFORMATION…
http://wle-mekong.cgiar.org/about/cpwf-in-
the-mekong/